The method and systems by which a taxpayer calculates the amount of
income, gains, losses, deductions, and credits and determines when these
items must be reported, constitute the taxpayer's method of tax
accounting. Although the Tax Code and the regulations authorize the use
of several accounting methods, and permit certain combinations of
methods, a taxpayer must use the accounting method on the basis of which
the taxpayer regularly computes book income. Further, the method must
be used consistently and must clearly reflect income.
A taxpayer's method of accounting includes not only the overall method of accounting, but also the accounting treatment of any item. The taxpayer may not treat a particular item in a manner that differs from the overall method.
After a taxpayer has adopted a particular method of accounting, either as an overall method of accounting or as a method of accounting for a particular material item, any changes in accounting method must first be approved by the IRS. The IRS may exercise its sole discretion in accepting a taxpayer's return as computed under the new method of accounting, unless the taxpayer has properly obtained its prior consent to the change.
A change in accounting method may be requested by a taxpayer or required by the IRS. The IRS usually must approve all changes in methods and may specify conditions for implementing the change. The IRS grants automatic consent to many accounting changes. Catch-up adjustments that prevent items of income and expenses from being omitted or reported twice, thereby avoiding possible post-change distortion of income, may be required.
The IRS has provided procedures for obtaining its consent to a change in accounting method. There are two types of consent—automatic consent and advance (non-automatic) consent. Both types of consent require taxpayers to file a Form 3115, Application for Change in Accounting Method. The advance consent procedures require payment of a user fee. The current IRS List of Automatic Changes is found in Rev. Proc. 2017-30.